4EIB:
reference: Crystal structure of circular permuted RoCBM21 (CP90): dimerisation and proximity of binding sites., Stephen P, Cheng KC, Lyu PC, PLoS One. 2012;7(11):e50488. doi: 10.1371/journal.pone.0050488. Epub 2012 Nov 30. PMID: 23226294

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).